Randomised controlled trials (RCTs) that evaluated the analgesic efficacy of intravenous naloxone following surgical procedures were eligible for inclusion. Naloxone could be administered as a continuous infusion or as part of an intravenous patient-controlled analgesia (PCA) regimen. The primary outcome of interest was the incidence of pruritis. Secondary outcomes included: incidence of postoperative nausea, emesis or sedation; and changes in opioid consumption and visual analogue pain scores. Eligible control groups did not receive intravenous naloxone (no further details specified).
The included trials were conducted in the USA, Columbia, Australia, China, Turkey and Taiwan. Surgery types were described as gynaecologic, hysterectomy, abdominal, orthopaedic and neurosurgical, or mixed. Most trials administered naloxone as part of an intravenous patient-controlled analgesia regimen; doses of naloxone varied. Morphine was the opioid used in all trials. All control groups received saline.
One reviewer selected studies for inclusion in the review; any uncertainties were resolved by discussion with another reviewer.